Shoe shining may be performed manually, or using a powered device.
Many people prefer their shoes to be manually polished using a compact brush as this tends to give a better result and allows all areas of the shoe to be covered. However, it can be tiring and/or expensive if using a shoe-shine service on a regular basis. On the other hand, powered devices typically consist of a large mains-powered machine that rotates in one direction. The device is not portable and requires mains power. Further, the device does not mimic the usual back and forth linear motion that manual brushing gives and cannot reach all areas.
Similarly, other applications such as wood sanding tend to achieve more desirable and accurate finishes with a portable reciprocating unit rather than a large rotating unit.